Johns Hopkins Health Alert
Food for the Eyes
Johns Hopkins doctors discuss the role that nutrients, such as lutein, beta carotene, zinc, and omega-3 fatty acids play in slowing the progression of age-related macular degeneration.
That tempting grilled fish and spinach salad may come with a side of eye protection. In 2006, the National Eye Institute (NEI) began to enroll 4,000 people with varying levels of age-related macular degeneration in a five-year study that will test whether two nutrients in green leafy vegetables and in fish can slow progression of the age-related macular degeneration.
Called AREDS (Age-Related Eye Disease Study) II, the study is somewhat similar to an earlier one, AREDS I, which established that other nutrients -- high-dose oral supplements containing beta carotene, zinc, copper, and vitamins C and E -- decrease age-related macular degeneration progression rates and vision loss.
Here’s a rundown on nutrients that may be serving your sight:
- Age-related macular degeneration and lutein and zeaxanthin -- These may sound like exotic European surnames, but they are carotenoids, the antioxidants found in brightly colored fruits and vegetables. Lutein and zeaxanthin (pronounced zee-uh-ZANthin) form the visible yellow pigment of the macula, the small spot at the center of the retina essential for central and detailed vision (such as reading vision).
Scientists believe that lutein and zeaxanthin may protect eyes from age-related macular degeneration. For one thing, they seem to act as a sunscreen, filtering out blue light, a harmful form of sunlight. Lutein and zeaxanthin also do what all antioxidants do: They protect cells from damage by free radicals, imbalanced oxygen molecules that attack healthy cells. And the nutrients may bulk up the macular pigment, also a factor associated with lower risk of age-related macular degeneration.
- Macular degeneration and fish oil -- Oily fish like salmon, tuna, and sardines are delicious picnics of omega-3 fatty acids, essential nutrients our bodies can’t manufacture. Some studies suggest an association between one of the acids, DHA (docosahexaenoic acid), and a lower risk of age-related macular degeneration, dry eye (lack of eye moisture), and glaucoma, an eye disease that damages the optic nerve. In fact, the first AREDS revealed that individuals who ingested foods richest in DHA -- the equivalent of two or more servings of fish per week -- had a 40% lower risk of having age-related macular degeneration. Although scientists are not certain how DHA protects the eye, both DHA and its fatty-acid partner eicosapentaenoic acid (EPA) are essential for the development and functioning of the retina, which is packed with DHA, and the brain.
- Macular degeneration and beta-carotene, vitamins C and E, zinc, and copper -- This combination of nutrients is the first effective treatment for slowing the progression of age-related macular degeneration. Scientists had suspected that these nutrients might help, based on early small studies. But in 2001, the NEI completed its first seven-year AREDS clinical trial, in a group of subjects that included people at risk for advanced age-related macular degeneration, cataracts, or both. More than 4,000 participants, most of whom had some degree of age-related macular degeneration, took high daily doses of the nutrients. The risk of age-related macular degeneration progression was reduced by 25% for those using the combination supplement who had been considered at greatest risk for progression.
This combination is now sold over-the-counter under the brand names Ocuvite PreserVision and Icaps AREDS Formula, but it is not appropriate for everyone with AMD. If you have AMD, talk to your eye doctor before taking either of these supplements, particularly if you are a smoker or have recently quit smoking. Beta carotene, one of the nutrients in the supplement, may increase the risk of lung cancer in smokers.
Posted in Vision on July 20, 2007
Reviewed September 2011
Medical Disclaimer: This information is not intended to substitute for the advice of a physician. Click here for additional information: Johns Hopkins Health Alerts Disclaimer
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